中文摘要：

目的：测定穿心莲内酯和脱水穿心莲内酯在正辛醇-水和正辛醇-缓冲液体系中的表观油水分配系数，为体内吸收研究提供参考。方法：采用摇瓶法测定穿心莲内酯和脱水穿心莲内酯的表观油水分配系数，采用HPLC法测定穿心莲内酯和脱水穿心莲内酯的浓度。结果：37℃下穿心莲内酯和脱水穿心莲内酯表观油水分配系数分别为3．90（10gPapp=0．59）和19．75（10gPapp=1．30）。结论：pH对穿心莲内酯和脱水穿心莲内酯表观油水分配系数有一定影响。在一定范围内，pH值增加可使穿心莲内酯和脱水穿心莲的表观油水分配系数减小。穿心莲内酯在pH6的磷酸盐缓冲液时表观油水分配系数最大[2．62（10gPapp=0．42）]，脱水穿心莲内酯则在pH5时达到最大[25．19（10gPapp=1．40）]。

英文摘要：

Objective：To determine the apparent n-octanol-water/ buffer partition coefficient of andrographolide and dehydroan- drographolide. Methods ： The apparent n-octanol-water/buffer partition coefficients of andrographolide and dehydroandrographolide were measured by shaking flask method. The concentrations of andrographolide and dehydroandrographolide were analyzed by HPLC method. Results ： The Papp of andrographolide and dehydroandrographolide were 3.90 （ log Papp = 0. 59 ） and 19. 75 （ log Papp = 1.30） in water at 37℃, respectively. Conclusions：The apparent n-octanol-buffer partition coefficients of andrographolide and dehydroandrographolide are influenced by pH, and the higher pH may decrease the apparent n-octanol-buffer partition coefficients of them. Andrographolide has the highest partition coefficient in pH6, and dehydroandrogapholide in pH5.